Abstract: The present invention relates, generally, to scientific and medical system methods for diagnosis of implantable cardioverter defibrillator (ICD) lead conductor anomalies, in particular conductor migration and externalization within an ICD implantable cardiac lead. The method uses an “imaginary” component of the high frequency transmission line impedance having certain spectral changes that correspond to movements of the conductor or an “imaginary impedance”. This allows the detection of conductor migration and small insulation failures.

Abstract: Methods and systems for identifying dislodgement of an electrode, operably coupled to an implanted medical device, from fixation with the endocardium of a chamber of the heart of a patient can include obtaining a test electrogram, and measuring at least two parameters indicating a cavitary electrogram and taking an action, such as generating an electrode dislodgement alert and/or configuring the implanted medical device to disable therapy, when the cavitary electrogram is indicated. In embodiments, the two parameters include a test positive component magnitude and a test negative component magnitude. In embodiments, the test component magnitudes are compared to baseline component magnitudes determined from a baseline electrogram.

Abstract: Systems and methods for detecting lead anomalies by detecting overcurrent conditions caused by the delivery of high voltage test pulses configured to minimize patient sensation. Patient sensation is minimized by limiting the total charge delivered in either a positive or negative test pulse by limiting duration, and/or by cancelling nerve activations by delivery of an opposite phase cancellation pulse as part of a biphasic test pulse. Embodiments include high-speed H-bridge switches, and micro-coulomb test capacitors to control total charge and duration. Embodiments detect anomalies when an overcurrent circuit detects a current above a threshold passing through an electrode that is not directly energized.

Abstract: A method and system for the diagnosis of anomalies in a lead attached to an implantable medical device, such as an implantable cardioverter defibrillator (ICD), including an insulation breach resulting in a short circuit of the high-voltage shock pulse. Determination that the defibrillation pathway is shorted may be made by initial analysis of a Reference EGM and Diagnostic EGM and subsequent analysis of Differential Diagnostic EGMs. Upon determining if a specific defibrillation pathway is shorted, the nonessential defibrillation electrode of that pathway may be excluded from the defibrillation circuit, delivering defibrillation current only between functioning defibrillation electrodes. Alternatively, the ICD system can confirm the presence of a lead anomaly with one or more alternative diagnostic approaches. Patient and remote-monitoring alerts may be initiated.

Abstract: Scientific and medical system circuitry for diagnosis of implantable cardioverter defibrillator (ICD) lead conductor anomalies, in particular conductor migration and externalization within an ICD implantable cardiac lead. The system determines an “imaginary” component of the high frequency transmission line impedance having certain spectral changes that correspond to radially outward movements or local externalization of a conductor within a lead body allowing for the detection of conductor migration and small insulation failures.

Abstract: Method and apparatus for diagnosis of conductor anomalies, such as partial conductor failures, in an implantable lead for an implantable medical device are disclosed. In various embodiments, small changes in the lead impedance are identified by the use of a small circuit element that is incorporated as part of the distal end of the implantable lead. In various embodiments, the small circuit element is electrically connected to a lead conductor and/or electrode of the implantable lead. Methods of diagnosing conductor anomalies in accordance with these embodiments generate measured values that depend only on the impedance of the conductors and electrodes of the lead, and not on the behavior of the conductor-tissue interface and other body tissues.

Abstract: The present invention relates, generally, to scientific and medical system methods for diagnosis of implantable cardioverter defibrillator (ICD) lead conductor anomalies, in particular conductor migration and externalization within an ICD implantable cardiac lead. The method uses an “imaginary” component of the high frequency transmission line impedance having certain spectral changes that correspond to movements of the conductor or an “imaginary impedance”. This allows the detection of conductor migration and small insulation failures.

Abstract: A method and apparatus to detect anomalies in the conductors of leads attached to implantable medical devices based on the dynamical electrical changes these anomalies cause. In one embodiment, impedance is measured for weak input signals of different applied frequencies, and a conductor anomaly is detected based on differences in impedance measured at different frequencies. In another embodiment, a transient input signal is applied to the conductor, and an anomaly is identified based on parameters related to the time course of the voltage or current response, which is altered by anomaly-related changes in capacitance and inductance, even if resistance is unchanged. The method may be implemented in the implantable medical device or in a programmer used for testing leads.

Abstract: The invention relates to a method and apparatus for diagnosis of conductor anomalies, such as insulation failures, in an implantable medical device, such as an implantable cardioverter defibrillator (ICD), a pacemaker, or a neurostimulator. Insulation failures are detected and localized by identifying changes in electrical fields via surface (skin) potentials. Small variations in potential are detected along the course of the electrode near the site of insulation failure.

Abstract: Dislodgement of a defibrillation lead from the right ventricle to the right atrium is a rare complication associated with implantable cardioverter-defibrillators. However, such dislodgement deserves attention out of proportion to its low incidence because of the possibility to cause fatal proarrhythmia. Various embodiments are directed to algorithms for detecting lead dislodgement, including a primary algorithm that operates during baseline rhythm and a secondary algorithm that operates during detection of ventricular tachycardia or ventricular fibrillation to identify lead dislodgement during atrial fibrillation.

Abstract: The present invention relates, generally, to scientific and medical system methods for diagnosis of implantable cardioverter defibrillator (ICD) lead conductor anomalies, in particular conductor migration and externalization within an ICD implantable cardiac lead. The method uses an “imaginary” component of the high frequency transmission line impedance having certain spectral changes that correspond to movements of the conductor or an “imaginary impedance”. This allows the detection of conductor migration and small insulation failures.

Abstract: Active surveillance of potential lead anomalies in implanted medical leads utilizes test signal(s) delivered through an output current pathway and induced signals monitored via an independent monitor current pathway to detect for any reactions to the test signals in the induced signals. Various specific responses can be initiated if a potential insulation breach or anomaly in the implanted medical lead is identified due to detection of a “positive” test result in the induced signals on the monitor current pathway in reaction to a test signal applied to the output current pathway.

Abstract: A method and system for the diagnosis of anomalies in a lead attached to an implantable medical device, such as an implantable cardioverter defibrillator (ICD), including an insulation breach resulting in a short circuit of the high-voltage shock pulse. Determination that the defibrillation pathway is shorted may be made by initial analysis of a Reference EGM and Diagnostic EGM and subsequent analysis of Differential Diagnostic EGMs. Upon determining if a specific defibrillation pathway is shorted, the nonessential defibrillation electrode of that pathway may be excluded from the defibrillation circuit, delivering defibrillation current only between functioning defibrillation electrodes. Alternatively, the ICD system can confirm the presence of a lead anomaly with one or more alternative diagnostic approaches. Patient and remote-monitoring alerts may be initiated.

Abstract: Disclosed is a method for the diagnosis of conductor anomalies, such as an insulation failure resulting in a short circuit, in an implantable medical device, such as an implantable cardioverter defibrillator (ICD). Upon determining if a specific defibrillation pathway is shorted, the method excludes the one electrode from the defibrillation circuit, delivering defibrillation current only between functioning defibrillation electrodes. Protection can be provided against a short in the right-ventricular coil-CAN defibrillation pathway of a pectoral, transvenous ICD with a dual-coil defibrillation lead. If a short caused by an in-pocket abrasion is present, the CAN is excluded from the defibrillation circuit, delivering defibrillation current only between the right-ventricular and superior vena cava defibrillation coils. Determination that the defibrillation pathway is shorted may be made by conventional low current measurements or delivery of high current extremely short test pulses.

Abstract: The invention relates to a method and apparatus for diagnosis of conductor anomalies, such as insulation failures, in an implantable medical device, such as an implantable cardioverter defibrillator (ICD), a pacemaker, or a neurostimulator. Insulation failures are detected and localized by identifying changes in electrical fields via surface (skin) potentials. Small variations in potential are detected along the course of the electrode near the site of insulation failure.