Cardiac Pacemakers, Inc.

Jungkuk Kim

Qingsheng Zhu

Geng Zhang

Arthur L Olive

Jan-Pieter Heemels

Jesse W Hartley

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.

Autocapture pacing/sensing configuration

A cardiac pacing system that enhances the ability of a cardiac pacer to automatically detect whether a pacing stimulus results in heart capture or contraction. The cardiac pacing system includes a pacing 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 pacing electrodes to be utilized to sense an evoked response to the pacing stimulus. The cardiac pacing system utilizes the pacing 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 pacing stimulus results in capture.

A method for reducing the affects of intrinsic detection latency in a cardiac rhythm management device, wherein said method is initiated immediately prior to delivering a stimulation pulse to the heart tissue. A coincidence of intrinsic and cardiac rhythm management initiated stimulus or the delivery of a stimulation pulse proximate the time of an intrinsic event due to intrinsic detection latency may results in delivery of unnecessary backup stimulus and/or imprecise determination of a pacing threshold. When stimulating the heart, the timing sequence for delivering a stimulation pulse typically depends upon the timing of a previous intrinsic or device initiated event. Further, the method of the present invention reduces the affects of intrinsic detection latency thereby facilitating improved detection of capture and determination of capture threshold for minimizing power consumption while assuring therapeutic efficacy.

Pseudo-fusion management during automatic capture verification

An implantable cardiac rhythm management device includes a controller adapted to receive digitized electrocardiogram signals from leads placed on or in the heart. The device also incorporates an autosense algorithm which automatically adjusts the sensing threshold dependent upon an average or maximum amplitude of noise detected during a period following a sensed cardiac depolarization. The sensing threshold is automatically set on a beat-to-beat basis at a level such that the signal to noise ratio exceeds a preset value.

Automatic threshold sensitivity adjustment for cardiac rhythm management

An implantable cardiac rhythm management device 10 includes a microprocessor-based controller 28 adapted to receive digitized electrogram signals from leads 14 placed on or in the heart and incorporates an autosense algorithm which is called into play when an electrogram is detected that exceeds an event detect threshold ET and capable of adjusting a sensing threshold ST to improve detection of cardiac depolarization signals in the presence of noise. The sensing threshold is automatically set on a beat-to-beat basis at a level that is dependent on a predetermined percentage of the peak amplitude of a current and an immediately preceding sensed or paced beat. The event threshold ET, which is always set at 50% of the sensing threshold, provides noise discrimination. The predetermined percentage value applied to the average peak value in arriving at the sensing threshold ST is dependent upon relative amplitudes of electrogram excursions and the signal-to-noise ratio encountered.

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Roseville, MN, United States of America

Jungkuk Kim