Abstract: The present disclosure relates to an implantable medical device, in particular a cardiac defibrillator, comprising an implantable defibrillator configured to generate an electrical defibrillation signal, an implantable electrode connected with the implantable defibrillator by a lead and configured to deliver the electrical defibrillation signal to a patient, an implantable sensor configured to detect mechanical vibrations by the heart of the patient and to provide a detection signal based on the detected mechanical vibrations, and a controller configured to analyze the detection signal to determine at least one parameter characterizing the mechanical vibrations and to initiate a defibrillation operation of the implantable defibrillator based on the determined parameter characterizing the mechanical vibrations.

Abstract: The present invention relates to a method for connecting a strand of a multi-strand cable to an electrode of an implantable medical device. The method includes cutting a strand of the multi-strand cable lifting at least one of the free ends, stripping the end of the lifted strand, placing an electrode around the multi-strand cable to partially cover the end of the lifted and stripped stand, and connecting at least one portion of the stripped end of the strand to the electrode.

Abstract: The present disclosure relates to an implantable medical device, in particular a cardiac defibrillator, comprising an implantable defibrillator configured to generate an electrical defibrillation signal, an implantable electrode connected with the implantable defibrillator by a lead and configured to deliver the electrical defibrillation signal to a patient, an implantable sensor configured to detect mechanical vibrations by the heart of the patient and to provide a detection signal based on the detected mechanical vibrations, and a controller configured to analyze the detection signal to determine at least one parameter characterizing the mechanical vibrations and to initiate a defibrillation operation of the implantable defibrillator based on the determined parameter characterizing the mechanical vibrations.

Abstract: The present invention relates to a method for connecting a strand of a multi-strand cable to an electrode of an implantable medical device. The method includes cutting a strand of the multi-strand cable lifting at least one of the free ends, stripping the end of the lifted strand, placing an electrode around the multi-strand cable to partially cover the end of the lifted and stripped stand, and connecting at least one portion of the stripped end of the strand to the electrode.

Abstract: An active implantable medical device of the defibrillation/cardioverter type able to detect a post-therapy sinusal tachycardia. This device includes circuits and logic able to detect ventricular and atrial activity; episodes of tachycardia and deliver a therapy for defibrillation and/or cardioversion, and/or antitachycardia stimulation. The detected tachycardia are classified, and there is selective control for the delivery of therapy according to the type of detected tachycardia classified. The device conducts further analysis of tachycardia after delivery of a shock therapy and is able to determine the presence of a post-therapy sinusal tachycardia, preferably by recognition of a stable ventricular rate, a 1:1 association of ventricular and atrial rates, a ventricular heart rate that is located in a range corresponding to a slow ventricular tachycardia. The device also is able to inhibit the delivery of a therapy in the presence of determined post-therapy sinusal tachycardia.

Abstract: An active implantable medical device of the defibrillation/cardioverter type able to detect a post-therapy sinusal tachycardia. This device includes circuits and logic able to detect ventricular and atrial activity; episodes of tachycardia and deliver a therapy for defibrillation and/or cardioversion, and/or antitachycardia stimulation. The detected tachycardia are classified, and there is selective control for the delivery of therapy according to the type of detected tachycardia classified. The device conducts further analysis of tachycardia after delivery of a shock therapy and is able to determine the presence of a post-therapy sinusal tachycardia, preferably by recognition of a stable ventricular rate, a 1:1 association of ventricular and atrial rates, a ventricular heart rate that is located in a range corresponding to a slow ventricular tachycardia. The device also is able to inhibit the delivery of a therapy in the presence of determined post-therapy sinusal tachycardia.

Abstract: An active implantable medical device of the defibrillator/cardiovertor type with an improved tachycardia discrimination for utilizing the delivery of a therapy of defibrillation and/or cardioversion and/or antitachycardia stimulation in the ventricle and/or atrium. The atrial and ventricular activity is monitored, and suspected tachycardia episodes in the monitored activity is tested and confirmed, the stability of RR intervals and the stability of associated PR interval are analyzed. The classification discriminates tachycardias detected as between ventricular tachycardias and supra-ventricular tachycardias, and authorizes delivery of a shock therapy in the presence of a confirmed ventricular tachycardias, or inhibits delivery of a shock therapy in response to a confirmed supra-ventricular tachycardia. Where appropriate, the classification also releases an atrial therapy.

Abstract: A defibrillator output circuit utilizes an optically coupled signal for controlling an isolated electronic switch. Variants of the output circuit include coupling via phototransistors or photodiodes for the control of at least one electronic switch. An H-bridge circuit configuration with four switches is connected to a single energy storage capacitor for generating multiphasic shocks across a load. The polarity of the shocks is selectable. Optical coupling methods are employed for driving the high side switches in the H-bridge.

Abstract: An improved automatic sensing threshold control for cardiac rhythm detection in an implantable device. The improvement includes setting the sensing threshold according to the amplitude of both sensed signals corresponding to cardiac activity and sensed noise, for setting the threshold substantially below the sensed signal amplitude, but above the noise amplitude. The invention provides absolute refractory periods after pacing or sensing, followed by a retriggerable noise refractory period. Following sensing the device sets the sensing threshold to approximately one-fourth of the measured amplitude, and then increases the threshold when it detects noise.

Abstract: A method and apparatus for optimizing the sensing circuit of a tachyarrhythmia detector for use with direct heart (cardiac) electrodes. The method is applied to detection of ventricular fibrillation and multifocal ventricular tachyarrhythmia, with rejection of T wave and pacing artifact. The sensing circuit optimized with this method includes a third-order high-pass filter followed by at least one comparator, with the filter corner frequency near 16 Hz and the comparator threshold near 0.40 mV referred to the input, in-band.

Abstract: A configuration for generating single capacitor multiphasic shocks is disclosed, using an H-bridge with four switches to connect an energy storage capacitor to a load with selectable polarity. The improvement concerns referring the negative side of the shock generator to a supply voltage which is negative with respect to pacing and sensing ground, and to connect the battery positive terminal to this same ground. This configuration permits operating the low side switches in the H-bridge, the pace/sense circuits, and the control circuitry from negative supplies derived without inversion from the negative battery terminal.

Abstract: This invention provides an improved Holter function in an implantable device for arrhythrnia monitoring or therapy. One improvement consists of a zoom feature which stores information about an arrhythmia episode at several levels of detail, with increasing levels of detail corresponding to shorter recording periods, and with a way to display the relation in time of the recordings at different levels of detail. The invention also introduces a novel implantable Holter function called an event log, which records time-stamped events once each minute, on changes in detected rhythm, or on application of antiarrhythmia therapy. The invention also provides logic for arbitrating which arrhythmia episodes the device saves in its memory.

Abstract: Methods and apparatus for classifying cardiac rhythm by analyzing sensed atrial and ventricular heartbeats, and determining if the rhythm might be pace-terminable in a given chamber. The method maintains a histogram of the sensed beat interval in the chamber of interest and a second histogram of conduction time from the other chamber. The method classifies a rhythm as pace terminable in the given chamber when the intervals in that chamber are stable, and the conduction times to that chamber are unstable. It applies further criteria when the intervals in the given chamber are stable, and the conduction times are also stable. Antitachycardia pacing is deliverable to terminate tachyarrhythmias determined to be pace terminable.