Biotronik Crm Patent Ag

Biotronik Se Co. Kg

Dirk Müssig

Warren S Dabney

Jie Lian

Brian M Taff

J Christopher Moulder

Andrew B Kibler

Hannes Kraetschmer

Volker Lang

Larry Stotts

Jeffrey A Von Arx

Marcelo Baru

Wantjinarjo Suwito

Habib Homayoun

Christopher S De Voir

Lauren Kraiter

Garth Garner

R Hollis Whittington

Eric Austin

Kurt Swenson

Richard A Schomburg

Thomas Dörr

Alan Fryer

Sharon Lefkov

Michael V Orlov

Duane Patterson

Indra Nigam

Sharon Levkov

David F Ph D Hastings

A method of enhancing the signal-to-noise ratio (SNR) of measured electrocardiogram (ECG) signals is provided. The method includes the steps of providing at least three cardiac input signals derived from the measured ECG signals Sand forming a first estimate USfrom each of at least three pairs of input signals. Moreover, the method includes the steps of forming a second estimate USfrom each of at least three input signals; comparing Sthe polarity and the amplitude of a first and second estimate U, Uto at least one threshold T; generating Sa composite signal X, wherein the polarity and the amplitude of the composite signal X depend on the result of the comparison; and using Sthe generated composite signal X to produce an output signal with enhanced signal-to-noise ratio (SNR). Furthermore, a corresponding cardiac device is also provided.

Method of enhancing the signal-to-noise ratio (SNR) of measured electrocardiogram (ECG) signals and a cardiac device for use in detecting heartbeats

An implantable cardiac electrostimulator includes an atrial sensing channel generating an atrial sense event signal upon detection of atrial activity, a ventricular sensing channel generating a ventricular sense event signal upon detection of ventricular activity, a VES detector detecting ventricular extrasystoles, atrial and ventricular stimulation pulse generators, and a stimulation control unit. The stimulation control unit determines scheduled delivery times of atrial stimulation pulses (T(A)) and/or ventricular stimulation pulses (T(V)), and triggers delivery if no atrial sense event signal arises before the end of an atrial escape interval (VAI) timing out at T(A), or if no ventricular sense event signal arises before the end of a ventricular escape interval (VEI) timing out at T(V). T(A) and T(V) depend upon detection of a ventricular extrasystole, and proper atrioventricular synchrony is maintained by setting a physiologically adequate A-V-delay between T(A) and T(V).

Implantable electrostimulator

Method and apparatus that uses dual-chamber (RA-RV), three-chamber (BiA-RV, or RA-BiV), or four-chamber (BiA-BiV) implantable cardiac devices including pacemakers, defibrillators and cardioverters, which stimulate cardiac tissue electrically to control the patient's heart rhythm. The method and apparatus are further configured to create a far-field intra-atrial electrogram (AEGM) and a far-field intra-ventricular electrogram (VEGM) that are independently filtered, scaled, and then summed to form a composite far-field electrogram.

Method and apparatus for generating a composite farfield electrogram

A heart stimulator provides for a more appropriate yet simple setting of the AV-delay. The heart stimulator comprises a stimulation pulse generator adapted to generate electric stimulation pulses and connected to a ventricular stimulation electrode for delivering electric stimulation pulses. A sensing stage connected to an electrode for picking up electric potentials inside a ventricle is adapted to sense an excitation or a contraction of a heart chamber. A memory is adapted to store parameters defining a Bezier function determining the relationship between AV-delay values and heart rate and a control unit connected to said memory, said sensing stage and to said stimulation pulse generator, is adapted to determine an actual AV-delay based on an actual intrinsic heart rate or an actual stimulation rate and a non-linear smoothing interpolation between said parameters stored in said memory.

Heart stimulator using a Bezier function to define AV-delay values

Heart stimulator that stimulates at least a heart's right atrium and ventricle in an atrium asynchronous stimulation mode with an overdrive stimulation rate. Interposes one resynchronization cycle after a sensed atrial event to regain AV synchrony during otherwise asynchronous stimulation mode. Allows for pacing mode that can pace the atrium with an overdrive stimulation rate in dual-chamber asynchronous mode while maintaining the AV synchrony and is called DDI(R)+. In DDI(R)+, pacemaker performs an atrial asynchronous (V synchronous) pacing mode such as DDI or DDI(R). The overdrive stimulation rate (OSR) is either a fixed rate (programmed by the external device) that is thought to be above the underlying intrinsic atrial rate, or is dynamically adjusted according to the measured atrial cycle length to be slightly above intrinsic atrial rate. The overdrive stimulation rate may be based on an intrinsic atrial rate or on hemodynamic need. DDI(R)+ timing may be ventricle-based.

Atrial overdrive pacing in non-atrial tracking mode while maintaining AV synchrony

An implantable cardiac device is provided for adaptive ventricular rate smoothing during atrial fibrillation (AF). When AF is detected, the operation of the device is switched to non-atrial synchronized pacing mode such as DDI, DDIR, VDI, VDIR, VVI, or VVIR. The ventricular escape interval (VEI) is beat-by-beat modulated around a physiological interval zone (PIZ), which is determined by the pre-arrhythmia ventricular rate or the output of rate responsive sensor. The VEI remains unchanged if the preceding ventricular event is sensed and its RR interval is within the PIZ. Otherwise, the VEI is decreased asymptotically toward a lower interval threshold if the preceding RR interval is longer than the upper limit of the PIZ, or the VEI is increased asymptotically toward an upper interval threshold if the preceding RR interval is shorter than the upper limit of the PIZ. The step of incrementing or decrementing the VEI is adaptive to the absolute difference value between the preceding RR interval and the asymptotic interval threshold to ensure fast recovery of deviant RR interval toward the PIZ and to reduce the amount of high rate ventricular paces after a ventricular sense with very short coupling interval.

Adaptive ventricular rate smoothing during atrial fibrillation

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West Linn, OR, United States of America

Dirk Müssig