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Measuring pacing, threshold, capture margin, or contact impedance

Subclass of:

607 - Surgery: light, thermal, and electrical application

607001000 - LIGHT, THERMAL, AND ELECTRICAL APPLICATION

607002000 - Electrical therapeutic systems

607009000 - Heart rate regulating (e.g., pacing)

607027000 - Testing or monitoring pacer function

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Entries
DocumentTitleDate
20090054946EVALUATING THERAPEUTIC STIMULATION ELECTRODE CONFIGURATIONS BASED ON PHYSIOLOGICAL RESPONSES - A medical system comprises a plurality of electrodes; at least one sensor configured to output at least one signal based on at least one physiological parameter of a patient; and a processor. The processor is configured to control delivery of stimulation to the patient using a plurality of electrode configurations. Each of the electrode configurations comprises at least one of the plurality of electrodes. For each of the electrode configurations, the processor is configured to determine a first response of target tissue to the stimulation based on the signals, and a second response of non-target tissue to the stimulation based on the signals. The processor is also configured to select at least one of the electrode configurations for delivery of stimulation to the patient based on the first and second responses for the electrode configurations. As examples, the target tissue may be a left ventricle or vagus nerve.02-26-2009
20130030493METHODS FOR SETTING CARDIAC PACING PARAMETERS IN RELATIVELY HIGH EFFICIENCY PACING SYSTEMS - According to some methods, for example, preprogrammed in a microprocessor element of an implantable cardiac pacing system, at least one of a number of periodic pacing threshold searches includes steps to reduce an evoked response amplitude threshold for evoked response signal detection. The reduction may be to a minimum value measurable above zero, for example, as determined by establishing a ‘noise floor’. Alternately, amplitudes of test pacing pulses and corresponding post pulse signals are collected and reviewed to search for a break, to determine a lower value to which the evoked response threshold may be adjusted without detecting noise. Subsequent to reducing the threshold, if no evoked response signal is detected for a test pulse applied at or above a predetermined maximum desirable pulse energy, an operational pacing pulse energy is set to greater than or equal to the maximum desirable in conjunction with a reduction in pacing rate.01-31-2013
20130030492METHOD FOR DISCRIMINATING ANODAL AND CATHODAL CAPTURE - An implantable device and associated method detect anodal capture during electrical stimulation. A first pacing pulse is delivered using a first cathode and a first anode. A second pacing pulse is delivered using the first cathode and a second anode. A first response to the first pacing pulse and a second response to the second pacing pulse are measured. Anodal capture of the first pacing pulse at the first anode is detected in response to a first difference between the first response and the second response.01-31-2013
20130030491METHOD FOR DISCRIMINATING ANODAL AND CATHODAL CAPTURE - An implantable device and associated method discriminate between cathodal and anodal capture during electrical stimulation. A control response to a pacing pulse delivered using a candidate cathode electrode and a universal anode and responses to bipolar pacing pulses delivered using candidate bipoles including the candidate cathode are measured. Responsive to the control response meeting a threshold response, the control response is classified as normal and each of the responses for the candidate bipoles are compared to the control response. The responses for the candidate bipoles are each classified based on the comparison.01-31-2013
20090192563METHOD AND APPARATUS FOR ADJUSTING CARDIAC EVENT DETECTION THRESHOLD BASED ON DYNAMIC NOISE ESTIMATION - An implantable cardiac rhythm management (CRM) device includes a sensing and detection circuit that senses at least one cardiac signal and detects cardiac electrical events from the sensed cardiac signal using a detection threshold that is adjusted based on a dynamic noise estimation. The sensed cardiac signal is filtered to produce a filtered cardiac signal having a signal frequency band and a noise signal having a noise frequency band. The noise frequency band is substantially different from the signal frequency band. A dynamic noise floor is produced based on the noise signal and used as the minimum value for the detection threshold. A cardiac electrical is detected when the amplitude of the filtered cardiac signal exceeds the detection threshold.07-30-2009
20130138174AUTOTHRESHOLD WITH SENSING FROM PACING CATHODE - Cardiac electrostimulation energy is delivered to a heart chamber of a subject according to a normal pacing mode using a set of implantable pacing electrodes. When a threshold test for the heart chamber is initiated and a sensing electrode independent from the set of pacing electrodes is unavailable for the heart chamber, cardiac electrostimulation energy is delivered to the subject according to a threshold test mode. The threshold test mode includes sensing a cardiac activity signal from a subject using a set of sensing electrodes that includes an electrode common to the set of pacing electrodes, and changing the electrostimulation energy and sensing a resulting cardiac activity signal using the set of sensing electrodes to determine the optimum electrostimulation energy for capture of the heart chamber.05-30-2013
20100042176TEMPORAL-BASED CARDIAC CAPTURE THRESHOLD DETECTION - A cardiac capture threshold may be determined using a test pulse and a backup pulse. Here, delivery of a test pulse is followed almost immediately by a non-conditional backup pulse of sufficient energy such that the backup pulse should always capture in the event the test pulse does not capture. The timing of the evoked response that follows the backup pulse may then be used to determine whether the test pulse or the backup pulse captured the cardiac tissue. In some embodiments morphology discrimination may be employed to determine whether an evoked response was triggered by the test pulse or the backup pulse. In some embodiments timing information associated with one or more features of the evoked response may be analyzed to determine whether an evoked response was triggered by the test pulse or the backup pulse.02-18-2010
20130046356HIGH PHRENIC, LOW CAPTURE THRESHOLD PACING DEVICES AND METHODS - Methods of highly selective cardiac tissue stimulation and devices for practicing the same, e.g., implantable segmented electrode devices, are provided. The methods and devices provide a previously unavailable high phrenic nerve capture voltage paired with a low pacing capture voltage threshold. The subject methods and devices provide a number of benefits. For example, patients who previously would have been required to have their resynchronization device turned off due to phrenic nerve capture will now be able to reap the benefits of resynchronization therapy.02-21-2013
20090043352Method and apparatus to perform electrode combination selection - The present invention involves approaches for selecting one or more electrode combinations. Various method embodiments can include implanting a plurality of cardiac electrodes supported by one or more leads in a patient, attaching the one or more leads to a patient external analyzer circuit, delivering electrical stimulation to the patient's heart using the plurality of cardiac electrodes and the analyzer circuit, evaluating, for each electrode combination of a plurality of electrode combinations of the plurality of cardiac electrodes, one or more first parameters and one or more second parameters produced by the electrical stimulation delivered using the electrode combination, the first parameters supportive of cardiac function consistent with a prescribed therapy and the second parameters not supportive of cardiac function consistent with the prescribed therapy, selecting one or more electrode combinations of the plurality of cardiac electrodes based on the evaluation, the one or more electrode combinations selected as being associated with the one or more first parameters and less associated with the one or more second parameters relative to other electrode combinations of the plurality of cardiac electrodes, programming an implantable pacing circuit to deliver a cardiac pacing therapy that preferentially uses the selected one or more electrode combinations relative to other electrode combinations of the plurality of cardiac electrodes, detaching the one or more leads from the analyzer circuit, attaching the one or more leads to the implantable pacing circuit, and implanting the implantable pacing circuit.02-12-2009
20090306737Atrial Capture Verification - Methods and systems for classifying cardiac responses to pacing stimulation and/or preventing retrograde cardiac conduction are described. Following delivery of a pacing pulse to an atrium of the patient's heart during a cardiac cycle, the system senses in the atrium for a retrograde P-wave. The system classifies the atrial response to the pacing pulse based on detection of the retrograde P-wave. The system may also sense for an atrial evoked response and utilize the atrial evoked response in classifying the cardiac pacing response.12-10-2009
20130060298DETECTION OF EXTRACARDIAC STIMULATION BY A CARDIAC RHYTHM MANAGEMENT DEVICE - A medical device system and associated method for controlling a cardiac rhythm management therapy detect extracardiac stimulation. Cardiac pacing pulses are delivered, and a cardiac electrical signal comprising myocardial depolarization and repolarization signals is acquired. A processor is configured to, responsive to the cardiac electrical signal, detect extracardiac capture due to the cardiac pacing pulse.03-07-2013
20090299432IMPEDANCE VARIABILITY ANALYSIS TO IDENTIFY LEAD-RELATED CONDITIONS - In general, the disclosure relates to techniques for calculating mean impedance values and impedance variability values to detect a possible condition with a lead or device-lead pathway or connection. In one example, a device may be configured to determine an impedance value for an electrical path based on a plurality of measured impedance values for the electrical path, wherein the electrical path comprises a plurality of electrodes, and to determine an impedance variability value based on at least one of the plurality of measured impedance values. The device may be further configured to determine a threshold value based on the determined impedance value and the impedance variability value, compare a newly measured impedance value for the electrical path to the threshold value, and indicate a possible condition of the electrical path based on the comparison.12-03-2009
20090270938CAPTURE THRESHOLD AND LEAD CONDITION ANALYSIS - An exemplary method includes performing a capture threshold assessment using a bipolar electrode configuration, deciding if capture occurred for a maximum energy value of the capture threshold assessment and, if capture did not occur, then performing a lead impedance test for the lead associated with the bipolar electrode configuration. Such a test may aim to detect an insulation defect and/or a conductor defect. Other exemplary methods, devices, systems, etc., are also disclosed.10-29-2009
20090076564Retrograde Atrial Sensing for Identifying Sub-Threshold Atrial Pacing - Atrial capture threshold testing is performed in accordance with an atrial capture threshold testing schedule. Monitoring for retrograde P-waves occurs at least during times other than times during which scheduled atrial capture threshold testing is performed. In response to detecting a retrograde P-wave indicative of sub-threshold atrial pacing during monitoring, an unscheduled atrial capture threshold test is performed and pacing of the atrium is adjusted based on the unscheduled atrial capture threshold test.03-19-2009
20120226329System for Seeking for an Optimal Configuration of a Bi-, Tri- or Multi-ventricular Cardiac Resynchronization Implanted Device - An apparatus and a system for seeking for an optimal configuration of a bi-, tri- or multi-ventricular cardiac resynchronization implantable medical device. This system includes ventricular pacing, a signal representative of an endocardial acceleration (EA) of a patient's heart, and isolating and pre-processing the EA signal to obtain an EA1 component and an EA2 component. The effectiveness of the current pacing configuration is evaluated by one or more composite indexes that combine at least two of the following parameters: peak-to-peak amplitude (PEA1) of the EA1 component; time occurrence (TstEA1) of the beginning of the EA1 component; time interval (LargEA1) between the beginning of the EA1 component and the moment of the energy peak of the EA1 component; and duration of systole (Syst), represented by the time interval between the beginning (TstEA1) of the EA1 component and the beginning (TstEA2) of the EA2 component.09-06-2012
20130165988EFFECTIVENESS OF VENTRICULAR SENSE RESPONSE IN CRT - A method for monitoring the effectiveness of VSR and for taking action to improve the effectiveness of VSRs, if they are determined to be ineffective, includes comparing the a VSR evoked electrogram to a template electrogram of a pure biventricular paced CRT beat. If the electrograms, or features thereof, are similar, the VSR is determined to be effective. If the VSR is determined to be ineffective, the AV delay of biventricular CRT is shortened in a step-wise fashion in an incremental manner.06-27-2013
20130165986DETECTION OF TARGET VEIN FOR CRT THERAPY - A method for selecting a target vein for left ventricular lead placement for cardiac resynchronization therapy includes determining electrical dispersion for the first coronary vein by calculating the difference between (i) activation time at a location of the vein that has the latest activation time of a plurality of locations in the vein and (ii) activation time at a location that has the earliest activation time of the plurality of locations. The method may further include (ii) determining whether the magnitude of the electrical dispersion for the vein meets or exceeds a predetermined threshold selecting the vein if the vein meets or exceeds the predetermined threshold; or (ii) selecting, among several veins, the vein that has the highest electrical dispersion.06-27-2013
20130165987FAULT TOLERANT PACING - Methods and/or devices may be configured to monitor the performance of pacing therapy and provide fault-tolerant operation to provide therapy in the event of certain failure modes occurring in the pacing delivery circuits, leads, and/or lead/tissue interfaces. Generally, the methods and/or devices may provide fault-detection, fault-recovery and fault-handling to, e.g., handle potential faults.06-27-2013
20100087891SYSTEMS AND METHODS FOR DIAGNOSING AN IMPLANTABLE DEVICE - A method for diagnosing an implantable cardiac device including a plurality of implanted leads may include: monitoring a plurality of parameters associated with the plurality of implanted leads; detecting a change in one of the parameters; evaluating at least one of the other parameters upon detection of the change; and diagnosing a problem with the implantable cardiac device based on the detected change and the evaluation. A system for diagnosing an implantable cardiac device including a plurality of implanted leads may include an implantable pacing device and a processor. The processor may be configured to: monitor a plurality of parameters associated with the plurality of implanted leads; detect a change in one of the parameters; evaluating at least one of the other parameters upon detection of the change; and diagnose a problem with the implantable cardiac device based on the detected change and the evaluation.04-08-2010
20100087892IMPLANTABLE MEDICAL DEVICE RESPONSIVE TO MRI INDUCED CAPTURE THRESHOLD CHANGES - Energy delivered from an implantable medical device to stimulate tissue within a patient's body is controlled. An electrical signal used to stimulate the tissue is changed from a first energy state to a second energy state during a magnetic resonance imaging (MRI) scan. The energy delivered is maintained at the second energy state after the MRI scan. A capture threshold of the tissue is then measured, and the energy delivered to the tissue is adjusted based on the measured capture threshold of the tissue.04-08-2010
20080294217MEDICAL DEVICE FOR MONITORING BIOLOGICAL SIGNALS - A medical device having a sensor for sampling a biological signal, the biological signal representing a signal waveform and forming a waveform vector composed of the biological signal samples, and a memory for storing a least two threshold vectors composed of boundary samples representing at least two boundaries related to the biological signal defining subspaces for the biological signal samples. One threshold vector is an upper threshold vector composed of upper boundary samples and the other threshold vector is a lower threshold vector composed of lower boundary samples. An evaluation unit connected to the sensor determines a similarity index (ASCI) by comparing each of the biological signal samples of the waveform vector to corresponding boundary samples of the threshold vectors, thus determining to which subspace each biological signal sample belongs to and creating a trichotomized signal vector, and calculating the signed correlation product of two trichotomized signal vectors.11-27-2008
20100036449Adaptive Windowing for Cardiac Waveform Discrimination - Cardiac devices and methods provide adaptation of detection windows used to determine a cardiac response to pacing. Adapting a detection window involves sensing a cardiac signal indicative of a particular type of cardiac pacing response, and detecting a feature of the sensed cardiac signal. The cardiac response detection window associated with the type of cardiac pacing response is preferentially adjusted based on the location of the detected cardiac feature. Preferential adjustment of the detection window may involve determining a direction of change between the detection window and the detected feature. The detection window may be adapted more aggressively in a more preferred direction and less aggressively in a less preferred direction.02-11-2010
20100268296CARDIAC RHYTHM MANAGEMENT SYSTEM WITH USER INTERFACE FOR THRESHOLD TEST - An implantable cardiac rhythm management system includes a user interface, such as an external programmer, for performing therapy energy threshold tests. The threshold tests allow the caregiver to determine the threshold energy at which paces capture the heart, i.e., cause a resulting contraction of the heart chamber to which the paces are delivered. The programmer provides recorded indications of the energy corresponding to each paced event, so that the caregiver can easily determine the point at which capture was lost. This recorded representation of pacing energy makes it easy for the caregiver to determine proper pacing thresholds to be used to ensure adequate pacing, while minimizing energy drain to prolong the useful life of the implanted device.10-21-2010
20110098775Adaptive Waveform Appraisal in an Implantable Cardiac System - Methods and implantable devices for cardiac signal analysis. The methods and devices make use of waveform appraisal techniques to distinguish event detections into categories for suspect events and waveform appraisal passing events. When adjustments are made to the data entering analysis for waveform appraisal, the waveform appraisal thresholds applied are modified as well. For example, when the data analysis window for waveform appraisal changes in length, a waveform appraisal threshold is modified. Other changes, including changes in sensing characteristics with which waveform appraisal operates may also result in changes to the waveform appraisal threshold including changes in gain, sensing vector, activation of other devices, implantee posture and other examples which are explained.04-28-2011
20090299431High Voltage Confirmation System Utilizing Impedance Data - Systems and methods for providing high voltage confirmation are disclosed. In various embodiments, impedance data can be used as a basis for determining the operation of a high voltage confirmation system. In some embodiments, measurements of impedance associated with the high voltage lead(s) can provide indication as to the condition of the lead(s). In some embodiments, faulty leads can yield impedance values that exceed a known threshold value. In some embodiments, such threshold value can be determined from a laboratory study of the leads under conditions that are similar to the operating conditions of implantable cardiac devices.12-03-2009
20100114232INITIATION TESTS AND GUIDELINES FOR IMPLEMENTING CARDIAC THERAPY - An exemplary system includes a programmer configured to instruct an implantable device and a qualification module with instructions to call for tests performed by an implantable device configured for delivery of CRT, to receive results from the tests, to analyze the results and to decide, based on the analysis, if the patient qualifies for automatic, implantable device-based optimization of one or more CRT parameters and, only if the patient qualifies for automatic, implantable device-based optimization of one or more CRT parameters, presenting a graphical user interface that comprises a selectable control to enable an algorithm of an implantable device to automatically optimize at least one of the one or more cardiac resynchronization therapy parameters. Other exemplary methods, devices, systems, etc., are also disclosed.05-06-2010
20090149908IMPLANTABLE HEART STIMULATING DEVICE, SYSTEM AND METHOD - In an implantable biventricular heart stimulating device, and a biventricular heart stimulating method, wherein operation takes place normally with a time VV between a pacing pulse delivered, or inhibited, by a first ventricular pacing circuit and a pacing pulse delivered, or inhibited, by a second ventricular pacing circuit, and wherein a time VV06-11-2009
20120109247PACING INTERVAL DETERMINATION FOR VENTRICULAR DYSSYNCHRONY - A left-ventricular pacing interval and a right-ventricular pacing interval for timing the delivery of pacing pulses to a left ventricle and a right ventricle of a heart, respectively, may be based an intrinsic conduction time interval between at least one of an atrial sensing event or an atrial pacing event of an atrial chamber of a heart and a ventricular sensing event of a ventricular chamber of the heart. In some examples, the left-ventricular pacing interval is based on the time interval, where the left-ventricular pacing interval is less than the time interval. In some examples, the right-ventricular pacing interval is based on the time interval, where the right-ventricular pacing interval is greater than the left-ventricular pacing interval and less than the time interval.05-03-2012
20100125308Calculation of the Atrioventricular Delay for an Active Implantable Metal Device - An active implantable medical device including circuits for calculating an atrio ventricular delay (AVD) period. The device is able to detect the atrial and ventricular events; calculate an AVD and to start the AVD on detection of a spontaneous or paced atrial event. The device is able to deliver a low energy ventricular stimulation pulse at the expiration of the AVD in the absence of a detected spontaneous ventricular event. To calculate the AVD, the device uses an acceleration sensor to deliver an endocardiac acceleration (EA) signal representative of the movements produced by the contractions of the atrial cavity; and analyzes the EA signal to identify and isolate in the EA signal a component corresponding to the fourth peak of endocardiac acceleration (PEA4) associated to the atrial activity, and to calculate the AVD based on a parameter of this component.05-20-2010
20100094371SYSTEMS AND METHODS FOR PAIRED/COUPLED PACING - A coupled/paired stimulus pulse is delivered to the heart at an inter-pulse interval following one of i) detection of an intrinsic depolarization or ii) delivery of a primary stimulus pulse. Capture resulting from the coupled/paired stimulus pulse is sensed for. In response to capture by a coupled/paired stimulus pulse, the inter-pulse interval is incrementally decreased by a first amount until there is no capture by a coupled/paired stimulus pulse. In response to no capture by a coupled/paired stimulus pulse, the inter-pulse interval is incrementally increased by a second amount greater than the first amount, until capture by a coupled/paired stimulus pulse is detected. Once capture is again detected, paired/coupled pacing is delivered at the inter-pulse interval which resulted in capture for a predetermined period of time or until loss of capture occurs.04-15-2010
20100125309Atrial Capture Test for An Active Implantable Medical Device - An active implantable medical device that is able to perform an atrial capture test. The device includes circuits for delivering atrial stimulation pulses, and testing atrial capture, namely to detect the occurrence of an atrial contraction after the application of an atrial stimulation pulse. An acceleration sensor is used to deliver an EA signal representative of the movements produced by the contractions of the atrial cavity. The EA signal is analyzed to recognize and isolate in this EA signal a component EA05-20-2010
20090099619Method for optimizing CRT therapy - A method to optimize CRT therapy using ventricular lead motion analysis, either radiographically or with three dimensional electromagnetic mapping, to determine whether focal dyssynchrony is present at baseline, and whether biventricular pacing improves synchronicity and fractional shortening, and if no improvement is evidenced, changing the timing offset, pacing configuration and/or repositioning the ventricular leads to optimize effectiveness of CRT therapy. Various uses of this method include: diagnostic, with temporary leads to determine presence or absence of dyssynchrony and response to pacing; and therapeutic, to guide lead placement and programming during implant of CRT, and to optimize reprogramming of CRT during follow-up.04-16-2009
20090276000PACING METHOD - A method for delivering physiological pacing includes selecting an electrode implant site for sensing cardiac signals, which is in proximity to the heart's intrinsic conduction system, where pacing stimulation results in a rhythm breaking out at an intrinsic location, and selected in response to a ratio of sensed P-wave amplitude to sensed R-wave amplitude.11-05-2009
20090043351Method and apparatus to perform electrode combination selection - Approaches for selecting an electrode combination of multi-electrode pacing devices are described. Electrode combination parameters that support cardiac function consistent with a prescribed therapy are evaluated for each of a plurality of electrode combinations. Electrode combination parameters that do not support cardiac function are evaluated for each of the plurality of electrode combinations. An order is determined for the electrode combinations based on the parameter evaluations. An electrode combination is selected based on the order, and therapy is delivered using the selected electrode combination.02-12-2009
20080275522Non-captured intrinsic discrimination in cardiac pacing response classification - Cardiac devices and methods discriminate non-captured intrinsic beats during evoked response detection and classification by comparing the features of a post-pace cardiac signal with expected features associated with a non-captured response with intrinsic activation. Detection of a non-captured response with intrinsic activation may be based on the peak amplitude and timing of the cardiac signal. The methods may be used to discriminate between a fusion or capture beat and a non-captured intrinsic beat. Discriminating between possible cardiac responses to the pacing pulse may be useful, for example, during automatic capture verification and/or a capture threshold test.11-06-2008
20110208262LEAD-CARRIED PROXIMAL ELECTRODE FOR QUADRIPOLAR TRANSTHORACIC IMPEDANCE MONITORING - An implantable medical device (IMD) provides quadripolar transthoracic impedance measurement capability by forming at least one of the two electrodes associated with the canister of the device on a lead proximate the canister.08-25-2011
20130218227CRITERIA FOR OPTIMAL ELECTRICAL RESYNCHRONIZATION DERIVED FROM MULTIPOLAR LEADS OR MULTIPLE ELECTRODES DURING BIVENTRICULAR PACING - Generally, the disclosure is directed one or more methods or systems of cardiac pacing employing a right ventricular electrode and a plurality of left ventricular electrodes. Pacing using the right ventricular electrode and a first one of the left ventricular electrodes and measuring activation times at other ones of the left ventricular electrodes. Pacing using the right ventricular electrode and a second one of the ventricular electrodes and measuring activation times at other ones of the left ventricular electrodes. Employing sums of the measured activation times to select one of the left ventricular electrodes for delivery of subsequent pacing pulses.08-22-2013
20080281373Implantable Heart Stimulator and Method for Operation Thereof - In an implantable heart stimulator and a method for operation thereof, stimulation pulses are delivered to a heart. The amplitude of the delivered stimulation pulses can be selectively set. For setting the amplitude, threshold searches are performed at selected time intervals. Each threshold search determines a threshold value required for achieving capture. The amplitudes of the respective stimulation pulses are set to a value that exceeds the determined threshold value by a safety margin. The safety margin is selected as a function of the selected time intervals.11-13-2008
20090276001METHOD OF CONTINUOUS CAPTURE VERIFICATION IN CARDIAC RESYNCHRONIZATION DEVICES - In bi-ventricular pacing devices (including CRT devices) analysis of myocardial electrogram signals in one ventricle (e.g., a left ventricle, or “LV”) can same ventricle, on a continuous (every pacing cycle), triggered, aperiodic and/or periodic basis. Rather than using an evoked-response principle as has been the basis of capture detection in prior art and other systems, a principle employed via the present invention uses evidence of inter-ventricular conduction (i.e., from the opposite chamber) and/or atrio-ventricular conduction as evidence of LOC, since a non-capturing pacing stimulus provided to a first chamber will allow the myocardial tissue of the first chamber to remain non-refractory and thus inter-ventricular and atrio-ventricular wavefront propagation and conduction can commence and be detected thereby revealing whether LOC has occurred.11-05-2009
20100137935LV THRESHOLD MEASUREMENT AND CAPTURE MANAGEMENT - The invention provides methods and apparatus for determining in a non-tracking pacing mode (e.g., DDI/R, VVI/R) whether a ventricular pacing stimulus is capturing a paced ventricle, including some or all of the following aspects. For example, increasing a ventricular pacing rate a nominal amount to an overdrive pacing rate higher than a most recent heart rate and evaluating a conduction interval from a first pacing ventricle to a second sensing ventricle and then continuing to monitor the underlying rate to ensure that a threshold testing pacing rate will not exceed a predetermined minimum interval and providing pacing stimulation to the first ventricle and sensing the second ventricle to determine whether the pacing stimulation to the first ventricle was one of sub-threshold and supra-threshold. The methods and apparatus are especially useful in conjunction with ensuring actual delivery of a ventricular pacing regime (e.g., cardiac resynchronization therapy or “CRT”).06-03-2010
20090187228AUTOCAPTURE PACING/SENSING CONFIGURATION - A cardiac electrical stimulation system that enhances the ability of the system to automatically detect whether an electrical stimulus results in heart capture or contraction. The cardiac electrical stimulation system may be utilized, for example, as a cardiac pacer or as a cardioverter defibrillator. The cardiac electrical stimulation system includes an electrical stimulation circuit that attenuates polarization voltages or “afterpotential” which develop at the heart tissue/electrode interface following the delivery of a stimulus to the heart tissue, which thereby allows the stimulation electrodes to be utilized to sense an evoked response to the electrical stimulus. The cardiac electrical stimulation system utilizes the stimulation electrodes to sense an evoked response, thereby eliminating the necessity for an indifferent electrode to sense an evoked response. The present invention allows accurate detection of an evoked response of the heart, to thereby determine whether each electrical stimulus results in capture.07-23-2009
20130218223CRITERIA FOR OPTIMAL ELECTRICAL RESYNCHRONIZATION DERIVED FROM MULTIPOLAR LEADS OR MULTIPLE ELECTRODES DURING BIVENTRICULAR PACING - Generally, the disclosure is directed one or more methods or systems of cardiac pacing employing a right ventricular electrode and a plurality of left ventricular electrodes. Pacing using the right ventricular electrode and a first one of the left ventricular electrodes and measuring activation times at other ones of the left ventricular electrodes. Pacing using the right ventricular electrode and a second one of the ventricular electrodes and measuring activation times at other ones of the left ventricular electrodes. Employing sums of the measured activation times to select one of the left ventricular electrodes for delivery of subsequent pacing pulses.08-22-2013
20080319501Systems, Devices and Methods for Monitoring Efficiency of Pacing - Various systems, methods, devices and arrangements are implemented for use in pacing of the heart. One implementation is directed to methods and systems for determining a pacing location in the right ventricle of a heart and near the His bundle. A pacing signal is delivered to the location in the right ventricle. The pacing signal produces a capture of a left ventricle. Properties of the capture are monitored. Results of the monitored capture are used to assess the effectiveness of the delivered pacing signal as a function of heart function. The heart function can be, for example, at least one of a QRS width, fractionation and a timing of electrical stimulation of a late activation site of a left ventricle relative to the QRS.12-25-2008
20080319500Systems, Devices and Methods Relating to Endocardial Pacing for Resynchronization - Tools and methods are particularly suited for certain cardiac conditions advantaged by pacing of the right and left ventricles from a lead in the right ventricle, e.g., to facilitate mechanically and/or electrically synchronous contractions for resynchronization. Certain aspects involve pacing and/or mapping by delivering pulses to a cardiac site useful for improving heart function as measured, e.g., by QRS width, fractionation, late LV activation timing, mechanical synchronicity of free wall and septal wall, effective throughput/pressure, or a combination thereof. Other specific aspects include: determining a pacing threshold, beyond the capture threshold, to improve heart function; delivering pulses of opposite polarity to achieve such heart-function improvement; bi-ventricular pacing from a lead in the right ventricle for such improved heart function; delivering pulses of opposite polarity at a site near the His bundle; electrode-based His-pacing, without penetrating the myocardium; generating and/or delivering multiple pacing profiles including a pacing profile that delivers pulses of opposite polarity and another pacing profile; delivering a pacing profile to generate a synchronous contraction of the septal wall and free wall of the LV from a RV pacing location; and treating one or more of distal LBBB and/or diffuse LBBB by pacing at a site near the His bundle.12-25-2008
20110224751CAPTURE DETECTION BASED ON PROPAGATED DEPOLARIZATION FROM A PACING SITE - A methods and devices for capture detection are based on sensing a propagated depolarization from a contralateral cardiac chamber. An intersite sensing interval is determined based on an intersite pacing delay and an intersite conduction delay associated with first and second pacing sites. Pacing pulses are delivered to the first pacing site and the second pacing site, the pacing pulses separated in time by the intersite pacing delay. An intersite sensing interval is timed. The process includes sensing, during the intersite sensing interval, at the first pacing site for a depolarization propagated to the first pacing site from the second pacing site. It a depolarization propagated from the second pacing site is not sensed, then capture of the first and second pacing sites is detected.09-15-2011
20090082826AUTOMATIC SIGNAL AMPLITUDE MEASUREMENT SYSTEM IN THE SETTING OF ABNORMAL RHYTHMS - A system for automatically evaluating the sensing and detection of physiological processes by an implantable medical device, such as an implantable cardiac stimulation device. The system includes an automatic testing algorithm which iteratively adjusts at least one of the threshold and gain settings of the device and evaluates the accuracy of the detection for refining the programming of the device. The algorithm can include sampling the physiological process beginning at a relatively low rate to avoid excessive burden on the processing and battery capacity available and progressively increasing the rate to obtain higher resolution data. The algorithm can also evaluate the observed physiological process for periodicity and can determine repetition of an irregular pattern, such as bigeminy, and use the determined pattern for predictive purposes to refine the programming of the device. The algorithm employs observation of a change in observed pattern as indicia for loss of proper detection.03-26-2009
20090198301Automatic Capture Verification using Electrocardiograms Sensed from Multiple Implanted Electrodes - Cardiac monitoring and/or stimulation methods and systems that provide one or more of monitoring, diagnosing, defibrillation, and pacing. Cardiac signal separation is employed for automatic capture verification using cardiac activation sequence information. Devices and methods sense composite cardiac signals using implantable electrodes. A source separation is performed using the composite signals. One or more signal vectors are produced that are associated with all or a portion of one or more cardiac activation sequences based on the source separation. A cardiac response to the pacing pulses is classified using characteristics associated with cardiac signal vectors and the signals associated with the vectors. Further embodiments may involve classifying the cardiac response as capture or non-capture, fusion or intrinsic cardiac activity. The characteristics may include an angle or an angle change of the cardiac signal vectors, such as a predetermined range of angles of the one or more cardiac signal vectors.08-06-2009
20080262559Method and apparatus for adjusting the sensing threshold of a cardiac rhythm management device - A method and apparatus for automatically adjusting the sensing threshold of cardiac rhythm management devices. The invention is particularly suited for implementation in devices such as implantable cardiac pacemakers and implantable cardioverter/defibrillators. A method and apparatus are provided in which a noise level and signal level for a sensing channel are determined for each cardiac cycle with the sensing threshold of the channel being adjusted in accordance therewith.10-23-2008
20090204169IMPLANTABLE HEART STIMULATING DEVICE AND METHOD - In an implantable heart stimulating device and a method of the operation thereof, device has a control circuit that detects an evoked responses to delivered pacing pulses and to carry out an automatic capture routine. The control circuit is arranged to automatically temporarily disable the automatic capture routine on the basis of at least one of the following criteria: 08-13-2009
20110144713AUTOMATIC ELECTRODE INTEGRITY MANAGEMENT SYSTEMS AND METHODS - This document discusses, among other things, systems and methods for automatic electrode integrity management. Interelectrode impedance is measured for various electrode combinations of an implantable cardiac function management device. The impedance data is processed, such as at an external remote server, to determine whether an electrode is failing or has failed, to select an alternate electrode configuration, to alert a physician or patient, to predict a time-to-failure such as by using population data, or to reprogram electrode configuration or other device parameters of the implantable cardiac function management device.06-16-2011
20090210024Method and Apparatus for Phrenic Stimulation Detection - Approaches for characterizing a phrenic stimulation threshold, a cardiac capture threshold, a maximum device parameter, and a minimum device parameter are described. A plurality of cardiac pacing pulses can be delivered by using a cardiac pacing device, a pacing parameter of the plurality of cardiac pacing pulses being changed between delivery of at least some of the pulses. One or more sensor signals can be evaluated to detect stimulation of the phrenic nerve by one or more of the plurality of cardiac pacing pluses. The evaluation of the one or more sensor signals and the pacing parameter can be compared to determine if a phrenic stimulation threshold is at least one of higher than a maximum device parameter and lower than a minimum device parameter.08-20-2009
20090240301Multi Channel Approach to Capture Verfication - Methods and systems involve classifying the cardiac response to pacing using a multi-channel approach. Multiple cardiac response signals are sensed via multiple sense channels. Each sense channel comprises a distinct combination of electrodes and sensing circuitry. The cardiac response to the pacing pulse is classified based on the morphology of the cardiac response signals. Classifying the cardiac response involves discriminating between capture, fusion, non-capture, and non-capture with intrinsic activity.09-24-2009
20090259272BUNDLE OF HIS STIMULATION SYSTEM - A system for therapeutically stimulating a His bundle includes an implantable pulse generator and a multi-polar medical electrical lead. The generator is configured for subcutaneous implantation and to generate a pacing stimulus. The lead includes a connector assembly, a flexible tubular body, a distal tip assembly and coil conductors. The body extends intravascularly from the generator to a location proximate the His bundle and includes a proximal end, a distal end, and a longitudinal lumen. The tip assembly includes an electrode, a fixation helix, and a shank portion. The helix extends to a location proximate the His bundle and is operable as an electrically isolated electrode. The shank portion extends within the lumen and includes a receptacle for receiving a stylet tip. The conductors extend longitudinally through the lumen and are coupled to the electrode and the helix. One or both of the conductors defines a stylet lumen.10-15-2009
20130218224CRITERIA FOR OPTIMAL ELECTRICAL RESYNCHRONIZATION DERIVED FROM MULTIPOLAR LEADS OR MULTIPLE ELECTRODES DURING BIVENTRICULAR PACING - Generally, the disclosure is directed one or more methods or systems of cardiac pacing employing a right ventricular electrode and a plurality of left ventricular electrodes. Pacing using the right ventricular electrode and a first one of the left ventricular electrodes and measuring activation times at other ones of the left ventricular electrodes. Pacing using the right ventricular electrode and a second one of the ventricular electrodes and measuring activation times at other ones of the left ventricular electrodes. Employing sums of the measured activation times to select one of the left ventricular electrodes for delivery of subsequent pacing pulses.08-22-2013
20130218225CRITERIA FOR OPTIMAL ELECTRICAL RESYNCHRONIZATION DERIVED FROM MULTIPOLAR LEADS OR MULTIPLE ELECTRODES DURING BIVENTRICULAR PACING - Generally, the disclosure is directed one or more methods or systems of cardiac pacing employing a right ventricular electrode and a plurality of left ventricular electrodes. Pacing using the right ventricular electrode and a first one of the left ventricular electrodes and measuring activation times at other ones of the left ventricular electrodes. Pacing using the right ventricular electrode and a second one of the ventricular electrodes and measuring activation times at other ones of the left ventricular electrodes. Employing sums of the measured activation times to select one of the left ventricular electrodes for delivery of subsequent pacing pulses.08-22-2013
20130218226CRITERIA FOR OPTIMAL ELECTRICAL RESYNCHRONIZATION DERIVED FROM MULTIPOLAR LEADS OR MULTIPLE ELECTRODES DURING BIVENTRICULAR PACING - Generally, the disclosure is directed one or more methods or systems of cardiac pacing employing a right ventricular electrode and a plurality of left ventricular electrodes. Pacing using the right ventricular electrode and a first one of the left ventricular electrodes and measuring activation times at other ones of the left ventricular electrodes. Pacing using the right ventricular electrode and a second one of the ventricular electrodes and measuring activation times at other ones of the left ventricular electrodes. Employing sums of the measured activation times to select one of the left ventricular electrodes for delivery of subsequent pacing pulses.08-22-2013
20100204746PACEMAKER PASSIVE MEASUREMENT TESTING SYSTEM AND METHOD - A system and method for passively testing a cardiac pacemaker in which sensing signal amplitudes and lead impedance values are measured and stored while the pacemaker is functioning in its programmed mode. The amplitude and impedance data may be gotten and stored periodically at regular intervals to generate a historical record for diagnostic purposes. Sensing signal amplitudes may also be measured and stored from a sensing channel which is currently not programmed to be active as long as the pacemaker is physically configured to support the sensing channel. Such data can be useful in evaluating whether a switch in the pacemaker's operating mode is desirable.08-12-2010
20120143278DETECTING IMPLANTED MEDICAL ELECTRICAL LEAD DISLODGEMENT USING CARDIAC SIGNALS - Evaluation of an implanted electrical lead condition includes comparing electrogram template features with test electrogram features. The evaluating also includes determining the implanted electrical lead condition based solely on the electrogram comparison. The compared test electrogram features and template electrogram features may be atrial amplitudes and ventricular amplitudes. The sensing may be with a quad polar lead. The compared test electrogram features and electrogram template features may account for different patient postures and/or may account for respiration modulation.06-07-2012
20100262207Methods and Systems for Managing Fusion and Noise in Cardiac Pacing Response Classification - Methods and systems for detecting noise in cardiac pacing response classification processes involve determining that a cardiac response classification is possibly erroneous if unexpected signal content is detected. The unexpected signal content may comprise signal peaks that have polarity opposite to the polarity of peaks used to determine the cardiac response to pacing. Fusion/noise management processes include pacing at a relatively high energy level until capture is detected after a fusion, indeterminate, or possibly erroneous pacing response classification is made. The relatively high energy pacing pulses may be delivered until capture is detected or until a predetermined number of paces are delivered.10-14-2010
20100198295PERFORMING EXTENDED CAPTURE DETECTION TEST AFTER DETECTING INADEQUATE CAPTURE - Techniques are described for performing an extended capture detection test after detecting inadequate capture during a first capture detection test. An example system includes an implantable medical device that delivers pacing pulses to a patient, that periodically performs a first capture detection test to detect capture or loss of capture of the pacing pulses, and that detects inadequate capture during the first capture detection test, wherein in response to detecting the inadequate capture, the implantable medical device performs a second capture detection test that is longer than the first test. The system also includes a programmer device that programs the implantable medical device and that retrieves data from the implantable medical device corresponding to the second capture detection test. The example system may conserve battery power and prevent loss of current by performing the extended capture detection test only after detection of inadequate capture during the first test.08-05-2010
20090105780Pacing Output Determination Based on Selected Capture Threshold Values - Approaches for adjusting the pacing energy delivered by a pacemaker are provided. Adjusting the pacing energy involves performing a plurality of capture threshold tests, each capture threshold test measuring a capture threshold of the heart. One or more measured captured thresholds are selected, including at least one capture threshold that is higher relative to other measured capture thresholds acquired by the plurality of capture threshold tests. The pacing energy is adjusted based on the one or more selected capture thresholds.04-23-2009
20110245890METHOD AND APPARATUS FOR PACING SAFETY MARGIN - An apparatus comprises a cardiac signal sensing circuit, a pacing therapy circuit, and a controller circuit. The controller circuit includes a safety margin calculation circuit. The controller circuit initiates delivery of pacing stimulation energy to the heart using a first energy level, changes the energy level by at least one of: a) increasing the energy from the first energy level until detecting that the pacing stimulation energy induces stable capture, or b) reducing the energy from the first energy level until detecting that the stimulation energy fails to induce capture, and continues changing the stimulation energy level until confirming stable capture or the failure of capture. The safety margin calculation circuit calculates a safety margin of pacing stimulation energy using at least one of a determined stability of a parameter associated with evoked response and a determined range of energy levels corresponding to stable capture or intermittent failure of capture.10-06-2011
20100063562LEADLESS TISSUE STIMULATION SYSTEMS AND METHODS - Systems including an implantable receiver-stimulator and an implantable controller-transmitter are used for leadless electrical stimulation of body tissues. Cardiac pacing and arrhythmia control is accomplished with one or more implantable receiver-stimulators and an external or implantable controller-transmitter. Systems are implanted by testing external or implantable devices at different tissue sites, observing physiologic and device responses, and selecting sites with preferred performance for implanting the systems. In these systems, a controller-transmitter is activated at a remote tissue location to transmit/deliver acoustic energy through the body to a receiver-stimulator at a target tissue location. The receiver-stimulator converts the acoustic energy to electrical energy for electrical stimulation of the body tissue. The tissue locations(s) can be optimized by moving either or both of the controller-transmitter and the receiver-stimulator to determine the best patient and device responses.03-11-2010
20120172945Retrograde Atrial Sensing for Identifying Sub-Threshold Atrial Pacing - Atrial capture threshold testing is performed in accordance with an atrial capture threshold testing schedule. Monitoring for retrograde P-waves occurs at least during times other than times during which scheduled atrial capture threshold testing is performed. In response to detecting a retrograde P-wave indicative of sub-threshold atrial pacing during monitoring, an unscheduled atrial capture threshold test is performed and pacing of the atrium is adjusted based on the unscheduled atrial capture threshold test.07-05-2012
20110098776CARDIAC RHYTHM MANAGEMENT SYSTEM AND METHOD - A system and method for cardiac rhythm management, which includes an electrode system having at least one electrode and control circuitry coupled to the electrode system from which a first cardiac signal is sensed. The control circuitry includes a pulse circuit to produce electrical pulses at a first value to be delivered to the electrode system in a first cardiac region. At least one cardiac signal is sensed from a second cardiac region, where the cardiac signal includes indications of cardiac depolarizations from the second cardiac region which occurs in direct reaction to the electrical pulses delivered to the first cardiac region. The first value of the electrical pulses are then modified by a pulse adjustment circuit when a cardiac depolarization which occurs in direct reaction to the electrical pulse delivered to the first cardiac region is detected from the second cardiac region.04-28-2011
20110098774ESTIMATION OF DEDICATED BIPOLAR PACING VECTOR THRESHOLD - Methods and devices are described that allow estimation of an electrostimulation capture threshold, such as a dedicated bipolar pacing vector threshold. In an example, an equal-energy assumption between first and second pacing vectors can be used to estimate an electrostimulation capture threshold of a second pacing vector from a measured electrostimulation capture threshold of the first pacing vector and impedances of the first and second pacing vectors. In an example, a relationship between first and second pacing vectors can be determined from measured data, and a parameter of the relationship can be used with a measurement of an electrostimulation capture threshold of the first pacing vector to estimate an electrostimulation capture threshold of the second pacing vector.04-28-2011
20120035682SYSTEM AND METHOD FOR TESTING NEURAL STIMULATION THRESHOLD - Various system embodiments comprise a neural stimulator, a premature ventricular contraction (PVC) event detector, a heart rate detector, an analyzer, and a controller. The neural stimulator is adapted to generate a stimulation signal adapted to stimulate an autonomic neural target. The analyzer is adapted to, in response to a PVC event signal from the PVC event detector, generate an autonomic balance indicator (ABI) as a function of pre-PVC heart rate data and post-PVC heart rate data. Other aspects and embodiments are provided herein.02-09-2012
20120123496CONNECTIVITY DETECTION AND TYPE IDENTIFICATION OF AN IMPLANTED LEAD FOR AN IMPLANTABLE MEDICAL DEVICE - An implantable medical device (IMD) configured to detect lead connectivity as well as to identify lead type. Detecting lead connectivity provides, among other information, confirmation that the lead is connected to the IMD and that such connection has good integrity between the IMD and the electrodes of its leads. With positive affirmation regarding lead connectivity, the IMD can in turn accurately identify the lead type. Such connectivity and lead type information gives a physician enhanced confidence in using and/or reprogramming the IMD with respect to such leads.05-17-2012
20120303085METHODS AND APAPRATUS FOR MANUALLY SUSPENDING INTRATHORACIC IMPEDANCE FLUID STATUS MEASUREMENTS - The capability to suspend a patient alert relating to a monitored physiologic parameters addresses a need to selectively shut off a patient-alert signal or signals during the time a patient is being treated for an excursion in the parameter. Of course, in general a signal call attention to a patient's a potentially deleterious status or condition for which they should seek medical attention. Once a chronically-implanted monitoring device has detected or provided information about the parameter relative to a desired value, trend, or range and a clinician has been notified and intervened the alert signal is temporarily disabled for a predetermined period. That is, once the notification occurs and alert has served its purpose, the alert mechanism is selectively deactivated while the patient ostensibly begins to gradually correct the monitored physiologic parameter under a caregiver's direction and control. After which time, the alert will reactivate.11-29-2012
20110004264Systems and Methods for Ranking and Selection of Pacing Vectors - Approaches to rank potential left ventricular (LV) pacing vectors are described. Early elimination tests are performed to determine the viability of LV cathode electrodes. Some LV cathodes are eliminated from further testing based on the early elimination tests. LV cathodes identified as viable cathodes are tested further. Viable LV cathode electrodes are tested for hemodynamic efficacy. Cardiac capture and phrenic nerve activation thresholds are then measured for potential LV pacing vectors comprising a viable LV cathode electrode and an anode electrode. The potential LV pacing vectors are ranked based on one or more of the hemodynamic efficacy of the LV cathodes, the cardiac capture thresholds, and the phrenic nerve activation thresholds.01-06-2011
20080243203Intracardiac Polarization Signal Stabilization - Polarization signals, which represent voltages measured at a pacemaker electrode, are not constant and may drift. Polarization signal drift, which often precedes undesirable pace polarization artifacts, is more significant when the pacemaker is inhibited from providing an electrical stimulation to the patient's heart. The present invention provides an implantable system and methods for stabilization of a polarization signal. Electrical pulses may be applied to stabilize a polarization signal. In one implementation of the invention, polarization signal stabilization may be used as part of process to terminate tachycardia.10-02-2008
20110054560PACING, SENSING AND OTHER PARAMETER MAPS BASED ON LOCALIZATION SYSTEM DATA - An exemplary method generates a map of a pacing parameter, a sensing parameter or one or more other parameters based in part on location information acquired using a localization system configured to locate electrodes in vivo (i.e., within a patient's body). Various examples map capture thresholds, qualification criteria for algorithms, undesirable conditions and sensing capabilities. Various other methods, devices, systems, etc., are also disclosed.03-03-2011
20110054559PACING, SENSING AND OTHER PARAMETER MAPS BASED ON LOCALIZATION SYSTEM DATA - An exemplary method generates a map of a pacing parameter, a sensing parameter or one or more other parameters based in part on location information acquired using a localization system configured to locate electrodes in vivo (i.e., within a patient's body). Various examples map capture thresholds, qualification criteria for algorithms, undesirable conditions and sensing capabilities. Various other methods, devices, systems, etc., are also disclosed.03-03-2011
20130158623Method and Apparatus for Detecting Imminent Structural Failure of an Electrical Lead in an Implanted Cardiac Therapy Medical Device - A method and apparatus implementing the method, which is not dependent on monitoring the electrical impedance of the lead, detects imminent structural failure of an electrical lead in an implanted medical device, such as an implantable cardioverter-defibrillator (ICD) or a pacemaker. The approach is to monitor directly the mechanical load loss of the lead (a measure of the loss of structural integrity of the lead) rather than, as in the prior art, to infer it from the electrical impedance.06-20-2013
20110118804SYSTEM AND METHOD FOR PERFORMING A CAPTURE TEST BASED ON THE ANALYSIS OF A CARDIAC VECTOGRAM - A system and method for performing a capture test based on the analysis of a cardiac vectogram is described. An active medical device includes: circuits and control logic for delivering electrical stimulation pulses to a heart chamber; collecting electrical activity of the heart chamber and producing two distinct temporal components (V05-19-2011
20100121404IMPLANTABLE HEART STIMULATING DEVICE - Implantable heart stimulating device has at least one electrode lead provided with at least two electrodes adapted to be arranged for electrical stimulation of a heart, a pulse generating that applies stimulation pulses between the electrodes, wherein one of the electrodes is the cathode and the other is the anode, to achieve cathodal capture of heart tissue by the cathode electrode. An anodal capture detector detects anodal capture at the anode electrode. The device further has a control unit and if anodal capture is detected by the detection means, the control unit changes the pacing regimen in order to optimize the hemodynamics of the heart.05-13-2010
20110098773ESTIMATION OF DEDICATED BIPOLAR PACING VECTOR THRESHOLD - Methods and devices are described that allow estimation of an electrostimulation capture threshold, such as a dedicated bipolar pacing vector threshold. In an example, an equal-energy assumption between first and second pacing vectors can be used to estimate an electrostimulation capture threshold of a second pacing vector from a measured electrostimulation capture threshold of the first pacing vector and impedances of the first and second pacing vectors. In an example, a relationship between first and second pacing vectors can be determined from measured data, and a parameter of the relationship can be used with a measurement of an electrostimulation capture threshold of the first pacing vector to estimate an electrostimulation capture threshold of the second pacing vector.04-28-2011
20110098772SYTEMS AND METHODS FOR DETERMINING OPTIMAL ELECTRODE PAIRS FOR USE IN BIVENTRICULAR PACING USING MULTI-POLE VENTRICULAR LEADS - Techniques are provided for use by implantable medical devices for determining a preferred or optimal pair of electrodes for delivering biventricular pacing therapy. In one example, the implantable device is equipped with a right ventricular (RV) lead and a multi-pole left ventricular (LV) lead. Briefly, for each of a selected set of RV/LV electrode pairs, electrocardiac parameters are detected within a patient in which the device is implanted, including parameters representative of an intrinsic biventricular electrical separation between LV and RV and parameters representative of a mechanical contraction delay in the LV. An optimal RV/LV electrode pair is then determined for delivering biventricular pacing based on an analysis of the intrinsic biventricular electrical separation and the mechanical contraction delay. Pacing latency, pacing delay from LV to RV, and the maximum slope of an LV evoked response may be used as proxies or surrogates for mechanical contraction delay.04-28-2011
20090299433PACING SYSTEM ANALYZER HAVING THREE SENSING AND PACING CHANNELS - A pacing system analyzer (PSA) having three or more individually controllable sensing and pacing channels provides for testing and measurement during an operation for implanting a pacemaker having three or more sensing and pacing channels. The PSA allows control and adjustment of pacing parameters including cross-channel pacing parameters relating activities between any two of the three or more channels, such as atrioventricular and interventricular pacing delays. The PSA is also capable of, among other things, displaying real-time cardiac signals, measuring amplitude and slew rate of cardiac depolarizations, and measuring lead impedance for each of the sensing and pacing channels, as well as measuring time intervals between cardiac depolarizations in two different sensing and pacing channels. In one embodiment, the PSA includes individually controllable atrial, right ventricular (RV), and left ventricular (LV) sensing and pacing channels.12-03-2009
20100023084LEAD INTEGRITY TESTING TRIGGERED BY SENSED SIGNAL SATURATION - Techniques for performing a lead integrity test in response to, e.g., during or after saturation of a sensed signal, e.g., a cardiac electrogram (EGM) signal, are described. A lead integrity test may comprise one or more impedance measurements for one or more leads. Possible causes of saturation of a sensed signal include lead conductor or connector issues, or other lead related conditions. A lead integrity test triggered in response to the saturation may be able to detect any lead related condition causing the saturation. A lead integrity test triggered in response to the saturation may advantageously be able to detect an intermittent lead related condition, due to the temporal proximity of the test to the saturation.01-28-2010
20090198300System for Characterizing Patient Tissue Impedance for Monitoring and Treatment - A system provides early prediction of heart tissue malfunction and electrophysiological pathology by determining anatomical tissue impedance characteristics for use in medical patient monitoring and treatment decision making. At least one repository of data indicates multiple predetermined expected impedance value ranges for corresponding multiple impedance measurements taken at multiple particular different sites of at least one anatomical organ. An impedance measurement processor automatically determines whether multiple measured impedance values taken at multiple particular different sites of an anatomical organ using an invasive catheter are within corresponding multiple predetermined expected impedance value ranges derived from the at least one repository. An output processor automatically communicates data comprising at least one message to a destination. The at least one message includes data indicating whether the multiple measured impedance values taken at the multiple particular different sites of the anatomical organ are within the corresponding multiple predetermined expected impedance value ranges.08-06-2009
20120004700IDENTIFICATION OF PACING SITE - An implantable medical device applies an electric signal over two electrodes and measures the resulting electric signal over a candidate pair of neighboring electrodes on a lead for a first heart ventricle or over a candidate electrode of the lead and a case electrode. An impedance signal is determined for each candidate pair or electrode based on the applied signal and the measured resulting signal. A time difference between start of contraction in a second ventricle and the timing of local myocardial contraction as identified from the impedance signal at the site of the candidate pair or electrode is determined for each candidate pair or electrode. An optimal pacing electrode is selected to correspond to one of the electrodes of the candidate pair having the largest time difference or the candidate electrode having largest time difference.01-05-2012
20110166618System for Cardiac Arrhythmia Detection - 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 and for receiving a pace signal indicating occurrence of a heart pace pulse applied to the heart. A signal processor uses the received sampled data and pace signal in calculating, a first signal characteristic value comprising a time interval between occurrence of the pace pulse and a cardiac cycle characteristic and a second signal characteristic comprising an average of the time intervals determined over a multiple heart cycles. A comparator compares at least one of the first and second characteristic values with a threshold value to provide a comparison indicator. A patient monitor generates an alert message associated with the threshold in response to the comparison indicator indicating a calculated signal characteristic value exceeds the threshold value.07-07-2011
20100137934ADAPTER, ADAPTER RETAIL UNIT AND SYSTEM OF THE ADAPTER, AN IMPLANTABLE MEDICAL ELECTRONIC DEVICE AND AN ELECTRODE LINE - An adapter for temporary sterile electric connection of an implantable medical electronic device to an electrode line that is to be connected to the implantable medical electronic device during implantation for undistorted transmission of measured values detectable on the electrode line to the device.06-03-2010
20120158089LEAD 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
20100249867PHYSIOLOGICAL SIGNAL AMPLIFIER WITH VOLTAGE PROTECTION AND FAST SIGNAL RECOVERY - A physiological sense amplifier achieves fast recovery times following receipt of a large voltage, such as when a defibrillation pulse is delivered, without blanking. The recovery time may be less than one millisecond when polarization of surrounding tissue or the housing of the device is not present. The sense amplifier uses a feedback network to clamp the input voltage to a gain amplifier at a predetermined value when a predetermined threshold value is exceeded.09-30-2010
20120165897Rate Initialization and Overdrive Pacing for Capture Threshold Testing - Approaches for rate initialization and overdrive pacing used during capture threshold testing are described. Cardiac cycles are detected and the cardiac events of a cardiac chamber that occur during the cardiac cycles are monitored. The number of intrinsic beats in the cardiac events is counted. Initialization for a capture threshold test involves maintaining a pre-test pacing rate for the capture threshold test if the number of intrinsic beats in the cardiac events is less than a threshold. The pacing rate is increased for the capture threshold test if the number of intrinsic beats in the cardiac events is greater than the threshold.06-28-2012
20080269825Mechanical Ventricular Pacing Non-Capture Detection for a Refractory Period Stimulation (RPS) Pacing Therapy Using at Least One Lead-Based Accelerometer - A system and method for monitoring at least one chamber of a heart (e.g., a left ventricular chamber) during delivery of a refractory period stimulation (RPS) therapy to determine if the desired non-capture (i.e., lack of ventricular mechanical capture due to refractory period stimulation) occurs. The system includes an implantable or external cardiac stimulation device in association with a set of leads such as epicardial, endocardial, and/or coronary sinus leads equipped with motion sensor(s). The device receives and processes acceleration sensor signals to determine a signal characteristic indicative of chamber capture due to pacing stimulus delivery, non-capture due to RPS therapy delivery, and/or contractile status based on the qualities of evoked response to pacing stimulation.10-30-2008
20120215276SYSTEMS, DEVICES AND METHODS USED IN VERIFYING NEURAL STIMULATION CAPTURE - Various system embodiments comprise a neural stimulator, a premature ventricular contraction (PVC) event detector, a heart rate detector, an analyzer, and a controller. The neural stimulator is adapted to generate a stimulation signal adapted to stimulate an autonomic neural target. The analyzer is adapted to, in response to a PVC event signal from the PVC event detector, generate an autonomic balance indicator (ABI) as a function of pre-PVC heart rate data and post-PVC heart rate data. Other aspects and embodiments are provided herein.08-23-2012
20120253420CARDIAC RHYTHM MANAGEMENT SYSTEM AND METHOD - A system and method for cardiac rhythm management, which includes an electrode system having at least one electrode and control circuitry coupled to the electrode system from which a first cardiac signal is sensed. The control circuitry includes a pulse circuit to produce electrical pulses at a first value to be delivered to the electrode system in a first cardiac region. At least one cardiac signal is sensed from a second cardiac region, where the cardiac signal includes indications of cardiac depolarizations from the second cardiac region which occurs in direct reaction to the electrical pulses delivered to the first cardiac region. The first value of the electrical pulses are then modified by a pulse adjustment circuit when a cardiac depolarization which occurs in direct reaction to the electrical pulse delivered to the first cardiac region is detected from the second cardiac region.10-04-2012
20080300644Method for reducing phrenic nerve stimulation - Methods and devices for reducing phrenic nerve stimulation of cardiac pacing systems involve delivering a pacing pulse to a ventricle of a heart. A transthoracic impedance signal is sensed, and a deviation in the signal resulting from the pacing pulse may be used to determine phrenic nerve stimulation. Methods may further involve detecting the phrenic nerve stimulation from the pacing pulse by delivering two or more pacing pulse to the ventricle of the heart, and determining a temporal relationship. A pacing vector may be selected from the two or more vectors that effects cardiac capture and reduces the phrenic nerve stimulation. A pacing voltage and/or pulse width may be selected that provides cardiac capture and reduces the phrenic nerve stimulation. In other embodiments, a pacing pulse width and a pacing voltage may be selected from a patient's strength-duration curve that effects cardiac capture and reduces the phrenic nerve stimulation.12-04-2008
20120239106HIS CAPTURE VERIFICATION USING ELECTRO-MECHANICAL DELAY - Stimulation energy can be provided to a His-bundle to activate natural cardiac contraction mechanisms. Interval information can be used to describe a cardiac response to His-bundle stimulation, and the interval information can provide cardiac stimulation diagnostic information. For example, interval information can be used to discriminate between intrinsic conduction cardiac contractions and contractions responsive to His-bundle pacing.09-20-2012
20120271373METHOD AND DEVICE FOR DETECTING NOISE - The present invention generally relates to implantable medical devices, such as pacemakers, and, in particular, to a method and an implantable medical device capable of detecting the presence of noise caused by external noise sources. Voltages and/or impedances are measured over one or several electrode configurations. Based on the measured voltages and/or impedances, noise parameters are calculated, which are compared with reference values to detect the presence of noise. In another aspect of the invention, at least two different electrode configurations with different noise pick-up areas are used in the measurement. Relations between the noise parameters of the at least two vectors are calculated and compared with reference relations to detect the presence of noise.10-25-2012
20120323291Method and Apparatus to Perform Electrode Combination Selection - Approaches for selecting an electrode combination of multi-electrode pacing devices are described. Electrode combination parameters that support cardiac function consistent with a prescribed therapy are evaluated for each of a plurality of electrode combinations. Electrode combination parameters that do not support cardiac function are evaluated for each of the plurality of electrode combinations. An order is determined for the electrode combinations based on the parameter evaluations. An electrode combination is selected based on the order, and therapy is delivered using the selected electrode combination.12-20-2012
20120330372Methods and Systems for Selecting Capture Verification Modes - Methods and systems are directed to selecting from a variety of capture verification modes. A plurality of capture verification modes, including a beat by beat capture detection mode and a capture threshold testing mode without intervening beat by beat capture detection is provided. An efficacy of at least one of the capture verification modes is evaluated, and based on the evaluation, a capture verification mode is selected.12-27-2012
20110319957EARLY DETECTION OF LEAD FAILURE USING AN IMPEDANCE HISTOGRAM - Testing lead conditions in an implantable medical device includes continuously sampling the impedance values of a lead associated with the implantable medical device. The sampling is conducted over a predetermined period of time. An impedance histogram is then generated using the sampled impedance values by separating each measured impedance value into a specific bin assigned to contain a particular range of impedance levels. The lead condition of the tested lead can then be determined based on one or more characteristics of the impedance histogram.12-29-2011
20120101546METHOD AND APPARATUS TO DETERMINE THE RELATIVE ENERGY EXPENDITURE FOR A PLURALITY OF PACING VECTORS - A medical device system determines and displays relative energy expenditure information for programmable parameter values. The system establishes a programmable parameter and multiple values of the parameter to be compared. A module performs a measurements for each of the multiple values and related to energy expenditure of a battery of an implantable medical device when operating according to each of the multiple parameter values. An energy expenditure for each of the values is computed using the measurements, and a graphical user interface is generated for displaying information corresponding to the computed energy expenditure for multiple parameter values.04-26-2012
20120101545IMPLANTABLE MEDICAL DEVICE IMPEDANCE MEASUREMENT MODULE FOR COMMUNICATION WITH ONE OR MORE LEAD-BORNE DEVICES - Example techniques for communicating between two medical devices are described. One medical device may be an implantable medical device. Another medical device may be a lead-borne implantable medical device. The lead-borne implantable medical device may be referred to as a satellite. The implantable medical device may measure impedance of a path including at least two electrodes, at least one of which is on the lead, using an impedance measurement module. In some example implementations of this disclosure, the implantable medical device may also use the impedance measurement module to communicate with the satellite on the lead.04-26-2012
20120101544NON-PROGRAMMING ACTIVATION DEVICE FOR SWITCHING MODES OF AN IMPLANTABLE MEDICAL DEVICE AND METHODS FOR SAME - When a medical procedure is performed on a patient in whom an implantable medical device is implanted, the medical procedure may have undesired effects on the medical device, such as triggering a response that initiates therapy by the device that is unnecessary and potentially dangerous to the patient. Systems and methods may facilitate performing of such medical procedures on such patients by automatically reprogramming the medical device, monitoring for one or more detectable characteristics associated with the medical procedure to be performed, and automatically restoring normal operation of the IMD after the medical procedure is completed.04-26-2012
20120101543CAPTURE THRESHOLD MEASUREMENT FOR SELECTION OF PACING VECTOR - Various techniques for selecting a pacing vector based on pacing capture thresholds are described. One example method described includes for each of a plurality of vectors, iteratively delivering at least one pacing stimulus at each of a plurality of magnitudes within a predetermined range of magnitudes to a first chamber, determining if a depolarization occurred in a second chamber of the heart within a predetermined threshold time interval after the pacing stimulus that is less than an interval, identifying a pacing stimulus for which a depolarization in the second chamber does not occur within the predetermined threshold time interval, determining a capture threshold magnitude for the vector based on the magnitude of the pacing pulse for which a depolarization in the second chamber does not occur within the predetermined threshold time interval, and recording the capture threshold magnitudes.04-26-2012
20100168813Capture Verification Using An Evoked Response Reference - A method and system for verifying capture in the heart involves the use of pacing artifact templates. One or more pacing artifact templates characterizing a post pace artifact signal associated with a particular pace voltage or range of voltages are provided. A pacing artifact template is canceled from a cardiac signal sensed following a pacing pulse. Capture is detected by comparing the pacing artifact canceled cardiac signal to an evoked response reference. Fusion/pseudofusion detection involves determining a correlation between a captured response template and a sensed cardiac signal.07-01-2010
20100168814Method and System for Detecting Capture with Cancellation of Pacing Artifact - Methods and systems for detecting capture using pacing artifact cancellation are described. One or more pacing artifact templates are provided and a cardiac signal is sensed in a cardiac verification window. Each of the pacing artifact templates may characterize the pacing artifact associated with a particular pacing energy level, for example. A particular pacing artifact template is canceled from the cardiac signal. Capture is determined using the pacing artifact canceled cardiac signal. Detection of fusion/pseudofusion beats may be accomplished by comparing a cardiac signal to a captured response template.07-01-2010
20130013020Methods and Systems for Managing Fusion and Noise in Cardiac Pacing Response Classification - Methods and systems for detecting noise in cardiac pacing response classification processes involve determining that a cardiac response classification is possibly erroneous if unexpected signal content is detected. The unexpected signal content may comprise signal peaks that have polarity opposite to the polarity of peaks used to determine the cardiac response to pacing. Fusion/noise management processes include pacing at a relatively high energy level until capture is detected after a fusion, indeterminate, or possibly erroneous pacing response classification is made. The relatively high energy pacing pulses may be delivered until capture is detected or until a predetermined number of paces are delivered.01-10-2013
20130013019Dynamic Morphology Based Atrial Automatic Threshold - Methods and systems for performing capture threshold tests are described. During an initialization procedure a capture detection interval and capture detection threshold are determined based on peak values of cardiac signals sensed following the supracapture threshold initialization pulses. Following initialization, a plurality of pacing pulses to the atrium are delivered and the peak values of the cardiac signals sensed following each of the plurality of pacing pulses are determined. The peak values are compared to the pacing artifact threshold and the capture detection threshold. A timing of each of the peak values is compared to the capture detection interval. For each pacing pulse, discrimination between a captured response, a noncaptured response, and a fusion response is based on the peak value and timing comparisons.01-10-2013
20100131027Methods and Systems for Selecting Capture Verification Modes - Methods and systems are directed to selecting from a variety of capture verification modes. A plurality of capture verification modes, including a beat by beat capture detection mode and a capture threshold testing mode without intervening beat by beat capture detection is provided. An efficacy of at least one of the capture verification modes is evaluated and, based on the evaluation, a capture verification mode is selected.05-27-2010
20130018433MANAGEMENT OF FUSION BEAT DETECTION DURING CAPTURE THRESHOLD DETERMINATION - An improved technique is described for dealing with the detection of fusion beats when capture verification is performed by a cardiac pacing device such as during a capture threshold determination procedure. Schemes for classifying heart beats may misclassify beats as fusion beats due to feature/m orphology changes in the test electrogram waveform that may occur even when capture is achieved.01-17-2013
20080234777MULTI-CHAMBER VENTRICULAR AUTOMATIC CAPTURE METHOD AND APPARATUS FOR MINIMIZING TRUE AND BLANKING PERIOD INDUCED VENTRICULAR UNDERSENSING - An implantable cardiac stimulation device and associated method perform a true or blanking period ventricular undersensing detection algorithm in response to ventricular loss of capture not associated with fusion or a change in capture threshold. The test identifies an originating cause of loss of capture, which may be ventricular undersensing of intrinsic R-waves or premature ventricular contractions occurring during a ventricular blanking period or atrial undersensing of P-waves resulting in blanking period ventricular undersensing. A corrective action is taken to reduce the likelihood of blanking period ventricular undersensing by automatically adjusting device operating parameters. The corrective action may include automatic adjustment of atrial sensitivity, shortening of the ventricular blanking period, or adjustment of the base stimulation rate. Minimizing the blanking period ventricular undersensing improves device performance by avoiding back-up stimulation and minimizing the risk of pacemaker competition-induced arrhythmias.09-25-2008
20130138175HYBRID AUTOTHRESHOLD - An apparatus comprises a control circuit that initiates a normal pacing mode for delivery of electrostimulation energy to the heart chamber. In response to an indication to initiate a threshold test, the control circuit determines an electrode configuration used to deliver the electrostimulation energy in the normal pacing mode, selects a first threshold test mode when a sensing electrode independent from the set of pacing electrodes is unavailable for the heart chamber, wherein a cardiac activity signal is sensed using a set of sensing electrodes that includes an electrode common to the set of pacing electrodes, and selects a second threshold test mode when a sensing electrode independent from the set of pacing electrodes is available for the heart chamber, wherein the cardiac activity signal is sensed using a set of sensing electrodes that excludes an electrode common to the set of pacing electrodes.05-30-2013
20130103109Leadless Cardiac Pacemaker Triggered by Conductive Communication - A leadless cardiac pacemaker configured for implantation in electrical contact with a left ventricular cardiac chamber and configured for leadless triggered left-ventricular pacing for cardiac resynchronization therapy (CRT) in response to conducted signals from a pulse generator.04-25-2013
20130103110ADAPTIVE SAFETY PACING - Methods and systems involve adjusting an energy used for safety pacing based on the capture threshold. The safety pacing energy may be adjusted prior to a capture threshold test. During the capture threshold test, backup safety paces are delivered using the adjusted pacing energy. Following suspension of automatic capture verification, the device may enter a suspension mode. During the suspension mode, safety pacing pulses are delivered using a pacing energy adjusted based on capture threshold.04-25-2013
20100286743Methods and Systems for Mitigating the Occurrence of Arrhythmia During Atrial Pacing - Noncaptured atrial paces can result in long-short cardiac cycles which are proarrhythmic for ventricular tachyarrhythmia. Approaches are described which are directed to avoiding proarrhythmic long-short cycles. For cardiac cycles in which the atrial pace captures the atrium, a first post ventricular refractory period (PVARP) and a first A-A interval are used. For cardiac cycles in which the atrial pace does not capture the atrium, both an extended PVARP and an extended A-A interval are used. The A-A interval following a noncaptured atrial pace is extended from an atrial depolarization sensed during the extended PVARP.11-11-2010
20130150913METHOD AND SYSTEM FOR IDENTIFYING A POTENTIAL LEAD FAILURE IN AN IMPLANTABLE MEDICAL DEVICE - A method for detecting potential failures by a lead of an implantable medical device is provided. The method includes sensing a first signal over a first channel between a first combination of electrodes on the lead and sensing a second signal from a second channel between a second combination of electrodes on the lead. The method determines whether at least one of the first and second signals is representative of a potential failure in the lead and identifies a failure and the electrode associated with the failure based on which of the first and second sensed signals is representative of the potential failure. Optionally, when the first and second sensed signals are both representative of the potential failure, the method further includes determining whether the first and second sensed signals are correlated with one another. When the first and second sensed signals are correlated, the method declares an electrode common to both of the first and second combinations to be associated with the failure.06-13-2013
20100318154SYSTEM AND METHOD FOR TESTING NEURAL STIMULATION THRESHOLD - Various system embodiments comprise a neural stimulator, a premature ventricular contraction (PVC) event detector, a heart rate detector, an analyzer, and a controller. The neural stimulator is adapted to generate a stimulation signal adapted to stimulate an autonomic neural target. The analyzer is adapted to, in response to a PVC event signal from the PVC event detector, generate an autonomic balance indicator (ABI) as a function of pre-PVC heart rate data and post-PVC heart rate data. Other aspects and embodiments are provided herein.12-16-2010
20100318153METHOD AND SYSTEM FOR AUTOMATICALLY SWITCHING BETWEEN MODES OF AN IMPLANTABLE MEDICAL DEVICE - An implantable medical device includes a lead, a pulse generator, an autocapture module, an autothreshold module, a fusion detection module, and a control module. The lead includes electrodes configured to be positioned within a heart. At least one of the electrodes is capable of sensing cardiac signals. The pulse generator delivers a stimulus pulse through at least one of the electrodes. The autocapture module senses an evoked response of the heart after delivery of the stimulus pulse when operating in an autocapture mode. The autothreshold module performs a threshold search when operating in an autothreshold mode. The fusion detection module identifies fusion-based behavior in the heart. The control module automatically switches between the autothreshold and autocapture modes based on a presence of the fusion-based behavior.12-16-2010
20100318152METHOD AND SYSTEM FOR OVERDRIVING A HEART CHAMBER DURING A THRESHOLD SEARCH - An implantable medical device includes a lead, a pulse generator, an autothreshold module and a control module. The lead includes electrodes positioned within a heart. At least one of the electrodes senses cardiac signals. The pulse generator delivers a stimulus pulse through at least one of the electrodes. The autothreshold module performs a threshold search when operating in an autothreshold mode and causes atrial stimulus pulses to be delivered in an atrium of the heart at an overdrive rate during the threshold search. The control module determines an AV conduction time and applies an overdrive AV adjustment to the AV conduction time to generate an AV delay. The autothreshold module uses the AV delay in connection with delivering ventricular stimulus pulses to a ventricle of the heart.12-16-2010
20130184777SYSTEMS AND METHODS FOR ASSESSING AND EXPLOITING CONCURRENT CATHODAL AND ANODAL CAPTURE USING AN IMPLANTABLE MEDICAL DEVICE - Techniques are provided for use by an implantable medical device for assessing and controlling concurrent anodal/cathodal capture. In one example, the device delivers bipolar pacing stimulus while sensing a bipolar intracardiac electrogram (IEGM) and while adjusting a magnitude of the pacing stimulus. The device analyzes the bipolar IEGM signals to detect an indication of activation representative of concurrent anodal and cathodal capture. Preferably, the pulse magnitude is set relative to the anodal/cathodal capture threshold based upon clinician programming in response to the needs of the patient. In this manner, concurrent anodal and cathodal capture can be selectively activated or deactivated based on clinician instructions received from a device programmer or other external programming device. Techniques exploiting both bipolar and unipolar IEGM signals to assess and control concurrent anodal/cathodal capture are also described. Techniques for use with quad-pole leads to achieve dual-site or quad-site capture are also set forth.07-18-2013
20120029589PACEMAKER PASSIVE MEASUREMENT TESTING SYSTEM - A system and method for passively testing a cardiac pacemaker in which sensing signal amplitudes and lead impedance values are measured and stored while the pacemaker is functioning in its programmed mode. The amplitude and impedance data may be gotten and stored periodically at regular intervals to generate a historical record for diagnostic purposes. Sensing signal amplitudes may also be measured and stored from a sensing channel which is currently not programmed to be active as long as the pacemaker is physically configured to support the sensing channel. Such data can be useful in evaluating whether a switch in the pacemaker's operating mode is desirable.02-02-2012
20120035681SYSTEMS AND METHODS FOR ESTIMATING LEFT ATRIAL PRESSURE (LAP) IN PATIENTS WITH ACUTE MITRAL VALVE REGURGITATION FOR USE BY AN IMPLANTABLE MEDICAL DEVICE - Various techniques are provided for use with an implantable medical device for estimating cardiac pressure within a patient based on admittance (or related electrical values such as impedance or conductance) that takes into account the presence of acute MR within the patient. Briefly, the device detects an indication of acute MR, if occurring within the patient. The device also applies electrical fields to tissues of the patient and measures electrical parameters influenced by the electrical field, such as admittance, impedance or conductance. The device then estimates cardiac pressure within the patient based on the measured electrical parameter and the indication of acute MR. In one example, different linear correlation functions are used to convert admittance values to left atrial pressure (LAP) values depending upon the presence or absence of acute MR within the patient.02-09-2012
20120095521DETECTION OF HEART RHYTHM USING AN ACCELEROMETER - Various techniques for using an accelerometer to detect cardiac contractions are described. One example method described includes filtering a signal received by an electrical sensing channel of an implantable medical device (IMD) configured to detect electrical depolarizations of a heart of a patient, identifying a failure of the electrical sensing channel of the IMD based on the filtered signal and, in response to identifying the failure, initiating a mechanical sensing channel of the implantable medical device to identify mechanical cardiac contractions.04-19-2012

Patent applications in class Measuring pacing, threshold, capture margin, or contact impedance